Everything about List Of Stars With Confirmed Extrasolar Planets totally explained
The following are
lists of stars with confirmed extrasolar planets.
Extrasolar planets were first confirmed to be orbiting pulsars
PSR B1257+12 and
PSR B1620-26. These discoveries were announced in
1992 and
1993 respectively. The first extrasolar planet to be found orbiting a normal star,
51 Pegasi b, was first discovered to be orbiting
51 Pegasi in
1995.
Note that the masses of the
planets are (for the most part) lower bounds only. If a planet is detected by the
radial velocity method, no information is gained about the
inclination of the planet's plane of
orbit around its star, and a value for this is needed to calculate the
mass. It has become customary to assume arbitrarily that the plane is exactly lined up with the line of sight from Earth (this produces the lowest possible mass consistent with the spectral line measurements).
There are
282 planets listed — 277 orbiting
normal stars (63 in multiple planet systems, and 214 in single planet systems), 4 orbiting
pulsars, 1 orbiting an extreme horizontal branch star and 1 orbiting a
brown dwarf.
The planets are listed with indications of their approximate masses as multiples of
Jupiter's mass (M
J = 1.8986 × 10
27 kg) or multiples of
Earth's mass (M
E = 5.9736 × 10
24 kg), and have approximate distances in
astronomical units (1 AU = 1.496 × 10
8 km, distance between Earth and
Sun) from their parent stars. For more information on how planets may be detected, see
extrasolar planet.
At the moment, according to the
International Astronomical Union, there's no agreed system for designating planets orbiting around other stars, nor is there any plan to create a naming system for extra-solar planets
(External Link
). A trend that's gaining prominence uses a lower-case letter (starting with "b") to extend the star's designation. For example,
16 Cygni Bb is the first
extrasolar planet found around the star
16 Cygni B, itself a member of the triple star system
16 Cygni. Some extrasolar planets have been given unofficial names, but these are not sanctioned by the IAU which oversees astronomical naming, or used in the scientific literature.
Extrasolar planets
There are 60 known extrasolar planets for which the
true mass is estimatable. The majority of these
transit their stars, enabling determination of the inclination of their orbits and hence the true ratio of the masses of the planets to their parent stars. Given a firm determination of the parent star's parallax and some independent means of measuring the star's mass, an absolute value can be derived for the planet's mass. Note also that eclipsing binaries can only have their masses securely determined if spectra for both objects exist, whereas a planet won't have spectra, see for example the introduction in
ISBS. Transiting planets enable some confidence to be expressed in the lower limit of the spectroscopically determined mass being near to the real value, as inclination is perforce near edge on to the line of sight, however as a transiting system is still essentially a single line spectroscopic binary it's the
mass function, and not the mass, that's being determined, see section on single line spectroscopic binaries
here. The mass is dependent on a solid determination of the parent star's mass, a value that's generally not well known for singleton stars.
Others have been detected via
astrometry. The planets around
OGLE-2003-BLG-235L/MOA-2003-BLG-53L,
OGLE-2005-BLG-071L and
OGLE-2006-BLG-109L were detected through
gravitational microlensing, a method which gives the ratio of the mass of the planet to that of the parent star. In these three cases, the parent star has been directly detected, enabling a determination of the actual mass of the system and confirming the companions' planetary nature. Planets "B" and "C" orbiting the
pulsar PSR B1257+12 have their masses determined by detection of their gravitational effects on each other.
2M1207b's mass is derived from evolutionary models of substellar objects. The mass of all singleton stars are derived from evolutionary models.
Sorted by increasing right ascension of the parent star. Planets within a system sorted by increasing orbital period. Planets in multiple-planet systems are highlighted in yellow.
Candidate extrasolar planets
There are currently 222 known objects which are candidate extrasolar planets. The majority of these objects have been detected using the radial velocity method and consequently their true masses are unknown. This means that some of these objects may in fact be brown dwarfs or even dim
red dwarf stars. Others have been detected via
gravitational microlensing, for which only the mass ratio between the planet and the parent star is known. If the parent star hasn't been detected, the planet's true mass is unknown.
There are currently 164 known candidate planets in single-planet systems and 58 known candidate planets in 24 multiple-planet systems (14 with two planets, 8 with three, 1 with four, and 1 with five). Since detection methods are not sensitive to low-mass planets, these stars may have smaller planets that are below the limits of detectability, or are so far from the star that they've not yet been observed over an orbital period.
Sorted by increasing right ascension of the parent star. Planets within a system sorted by increasing orbital period. Planets in multiple-planet systems are highlighted in yellow.
